Improvement in boiler-furnaces



2 Sheets--Sheet .1.

L. STEVENS, Boiler-Furnaces.

' Patented July. 14, 1874.

WWW

UNITED STATES PATENT OFFICE.

LEVI STEVENS, OF WASHINGTON, DISTRICT ()F COLUMBIA.

IMPROVEMENT IN BOILER-FURNACES.

Specification forming part of Letters Patent No. 153,128, dated July 14,1874; application filed December 3, 1873.

CASE A.

To all whom it may concern:

Be it known that I,LEVI STEVENS, of Washin gton, in the county ofWashington and District of Columbia, have invented certain Improvementsin Boiler-Furnaces, of which the following is a specification:

My invention relates to an improved arrangement of gas and combustionchambers for puddling, heating, and smelting furnaces; and it consistsin a novel construction of the same, together with an arrangement ofsuperheaters and pipes.

Figure l is a front elevation of my improved furnace; Fig. 2, a verticallongitudinal section on the line as w of Fig. 1; Fig. 3, a transversehorizontal section on the line y y of Fig. 2; and Fig. 4 a verticalsection of a portion shown in detail.

I construct the walls A of any suitable size, and at the front extendthem sufficiently high above the grate to form an upper chamber, D, asrepresented in Fig. 2, there being at the rear of this chamber aprojecting horizontal wall or shelf, 0, which inclines slightly towardthe front, and forms a partial separation between the chamber D and thecombustionchamber below.

The grate consists of a perforated plate, or it may be of bars set at aninclination, as shown in Fig. 2, the front edge being nearly on'a linewith the projection O, and its rear end resting against a wall inclinedin the opposite direction, the rear or upper portion of which forms thebridge-wall O, in which there is a transverse passage, a, with "a seriesof vertical perforations, 0, opening out through the top of thebridge-wall, as shown in Fig. 2. This passage (1, as shown in Fig. 3,extends along the walls on each side of the grate, and terminate withholes at which open into the space under the grate, and which areprovided with slides b, the handles h of which project out through thefront wall, as shown in Figs. 2 and 3, and by which the holes a can beopened or closed at will. Air is supplied to these passages to byopenings I at the front, as shown in Figs. 1 and 2, these being arrangedone near each side, and opening into thespace directly in front of theinclined grate B. The

coal is fed into the upper chamber D through one or more doors, 0, andwhere it'rests upon the shelf 0 and the grate B, and from whence it isfed gradually down upon the grate as it is consumed, it thus operatingon the principle outside of the front wall, and at each of the openingsI is provided with a nozzle, 0, projecting into said openings, as shownin Figs. 2 and 3. Near the top of the chamber D an opening is madethrough the wall, from which a tube, E, extends downward, and terminatesin a hole through the wall into the space under the grate, as shown inFigs. 1, 2, and 4, and into the lower part or mouth of this tube E therealso fits a nozzle, 0, from the steampipe K, as represented in Figs. 3and 4.

With a furnace thus constructed the coal is fed into the chamber D, andas it passes down upon the grate it is there burned, the burning of thecoal upon the grate heating and partially roasting the mass of coalabove it, the gases from. which ascend into the chamber D, from whencethey are drawn off through the tube E by means of the steam-jet at itslower end, and from whence this gas, mingled with the superheated steam,passes through the grate, in contact with the burning coal thereon,where these mingled gases are effectually consumed. At the same time alarge volume of air is forced by the jets e in through the openings I,which, mingling with the other gases, keeps up an ample supply ofoxygen, a portion of this, when desired, being passed through the sideopenings a into the passage o, from whence it issues through theperforations 0 in the bridge-wall, where it mingles with the gases andsmoke from the grate, and thereby effects a most thorough combustion ofall the gases. By means of the slides b more or less of the mingledgases and air may be fed out through the bridge-wall and, when desired,the passage a may be shut off entirely, and all the incoming gas fromthe chamber D,

together withsuperheated steam from the jets e, and the air from thepassages I, may all be fed through the fire on the grate, though thiswill seldom or never be done.

I do not in thisapplicatiou claim, broadly, the method of utilizing fuelby combining the hot gases from the fire-chamber with steam, whethersuperheated or not, and with or without air, and injeetin g them intothe fire-chamber, as that is fully set forth in my applieatiou filedJuly 15, 1873, this being an improvement in the apparatus for moreperfectly applying or carrying out the said method.

Having thus described 11] y invention, what I claim is- 1. A furnaceprovided with the inclined LEVI STEVENS.

\Vitnesses:

W. G. DODGE, J 0s. '1. K. PLANT.

